(a) Field of the Invention
The present invention relates to an engine clutch control apparatus of a hybrid vehicle, and more particularly, to an apparatus and method for controlling an engine clutch of a hybrid vehicle that controls release of the engine clutch by calculating a clutch input torque of the engine clutch based on a charge torque of an integrated starter-generator.
(b) Description of the Related Art
Today, as an environment pollution concerns increase, use of pollution free energy has been more actively researched. Particularly, the exhaust gas from a vehicle is a contributor to air pollution in larger cities. Accordingly, to provide enhancement of fuel consumption and reduce exhaust gas, a hybrid vehicle has been developed.
Particularly, a hybrid vehicle uses power generated with an engine and a motor and is driven by appropriately using of the power generated by a combustion operation of the engine and power generated by a rotation of the motor using electrical energy that is stored at a battery. In the hybrid vehicle, a transmission mounted electric device (TMED) type transmission in which a drive motor and a transmission are connected is generally applied. In addition, to transfer power of the engine to a drive shaft, an engine clutch is mounted between the engine and the drive motor.
The hybrid vehicle may be driven in various driving modes such as an electric vehicle (EV) mode, which is a pure electric vehicle mode using power of a drive motor based on whether an engine clutch is coupled, a hybrid electric vehicle (HEV) mode using a torque of a motor as auxiliary power while using a torque of an engine as main power, and a regenerative braking (RB) mode that recovers energy and charges the battery using the energy by enabling the motor to generate electricity with braking and inertia energy upon driving by braking or inertia of the vehicle.
In other words, while driving in an EV mode, when a driver's request power is greater than motor power, the hybrid vehicle performs a control that couples the engine clutch to connect the engine and the motor. Further, when the driver disengages an accelerator pedal or when the hybrid vehicle may be driven with only motor power due to the minimal request power, the hybrid vehicle performs a control that releases the engine clutch. The engine clutch is released based on a clutch input torque of the engine clutch. However, since the clutch input torque may be inaccurate, when the engine clutch is released, while the clutch input torque is transferred to a drive shaft, sense of difference by torque cutoff occurs.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.